I've set up a vsftpd server with local users jailed within their home directories. Anyhow if I connect through a ftp client I can execute systemcalls with the "!" command. How can I configure vsftpd to deny those calls?
ftp> ! cat /etc/shadow
... Working! Contents of /etc/shadow will be visible ...
Update:
The problem was that the vsftpd server was running with root rights and thus being able to read the shadows file.
But the question is still there:
How can I disable those systemcalls in general?